The present invention relates to a pressure adjustment device, particularly for adjusting the closing pressure of medicine bottle stoppers during a ferruling operation.
As is known, the mouth of medicine bottles is provided with an outer collar on which the edge of a mushroom-shaped rubber closure stopper rests. In order to retain the stopper in a closed position, a ferrule is provided which is constituted by a metallic circular band whose upper and lower edges are folded above the stopper and below the collar of the bottle with an operation termed ferruling. The folding of the upper and lower edges of the ferrule is performed by means of rollers which act on the edges while the bottle is rotated.
In order to ensure the tight seal of the stopper on the mouth of the bottle, there is a presser element which keeps the stopper pressed on the collar of the bottle during the ferruling step.
This operation however requires an exact application of the force which presses on the stopper in order to avoid risks of breakage of the bottle and at the same time ensure the necessary tightness of the seal.